The present invention relates to a thermal battery formed from a heat pipe circuit and functioning like a battery to store or release heat or cold energy. Heat or cold energy is stored in the thermal battery and can be released for use later. Or, in the event too much heat or cold energy is supplied during the utilization of heat or cold energy, extra and unused heat or cold energy can be stored in the thermal battery. On the contrary, in the event insufficient heat or cold energy is supplied, additional heat can be provided by the thermal battery for use. With the thermal battery of the present invention, energy can be fully utilized.
It is known that a lot of energies, either heat or cold energy, are not effectively used or stored during utilization of the energies and therefore lose in the atmosphere and form waste heat which causes environmental pollution, poor working efficiency of equipment, and undesirable waste of energy. Proper recuperation, storage, and utilization of the otherwise lost heat or cold energies will not only minimize possible environmental pollution but also enhance the efficiency of energy utilization and achieve the object of energy saving.
To store and utilize heat or cold energies, an active control is generally designed for a heat storage or regeneration system. That is, in the system design of heat storage, a pump is included to transfer heat energy from a high temperature heat source to the heat storage via flowing working fluid. To utilize the stored heat energy, an electromagnetic valve is used under control to change flow path of the working fluid, so that energy stored in the heat storage is released to and used by a low temperature heat sink. There are two drawbacks found in such type of heat storage. First, the need of an operating pump to transfer the working fluid and an controlled electromagnetic valve to change the energy storing or releasing ability of the working fluid causes increased operation cost and power consumption. The heat storage shall be unworkable in case of a system failure. Second, change of the energy storage and release ability of the conventional heat storage is basically relied on the system piping design and therefore only two functions, i.e. energy storage and energy release, are available in its operating modes. It is impossible for both the heat supply side and the heat utilization side of the heat storage to operate at the same time during the heat utilization.